Fri Jan 25, 2013 at 16:52:12 PM EST

There's a good deal of crowing in conservative circles this week about the new 2012 numbers on union membership. Union membership nationally fell by about 400,000, to 14.4 million. Union membership in Pennsylvania declined 45,000, including 59,000 in the private sector.

Of course, for anyone who cares about, say, the American Dream, democracy, and rising living standards, the newest numbers are bad news. A simple chart put together by the Center for American Progress shows that unions are vital to the middle class. As unions have weakened, so has the share of income going to middle-income workers - and the gap between the 1% and the 99% has mushroomed.

As this blog has noted, inequality undermines not only economic opportunity, but it also slows economic growth and makes our democracy less responsive to typical families and the public good (and too responsive to rich special interests).

One silver lining in the new numbers is the great variation that exists across states. Unions are growing in some places. Another silver lining is that the weaker unions get, the more evidence we get that this is a bad thing. Evidence such as the fact that the top 1% of the population took home 93% of the increase in income in the United States in the last year for which we have data. And evidence such as the skills shortage in U.S. manufacturing: surprise, surprise, if you pay workers poorly and don't invest in them, you can't attract and retain the factory talent you need.

Fifteen years ago, we outlined why America needs "new unions for a new economy" - and noted that we couldn't see how to restore widely shared prosperity without a revival of unionism. The evidence for our position grows with each day.